docs: def get_genetic_map_HapMapII_GRCh37(self):
          """ Get International HapMap Consortium HapMap Phase II genetic map for Build 37.
  
          Returns
          -------
          dict
              dict of pandas.DataFrame HapMapII genetic maps if loading was successful, else None
          """
          if self._genetic_map_HapMapII_GRCh37 is None:
              self._genetic_map_HapMapII_GRCh37 = self._load_genetic_map(
                  self._get_path_genetic_map_HapMapII_GRCh37()
              )
  
          return self._genetic_map_HapMapII_GRCh37